This invention is directed to an inventive mixing device. Specifically, this invention is directed to a mixing device for combining dry constituents with water to form a cement. More specifically, this invention is directed to a portable device for mixing gypsum cement with water to form a thin slurry where the device is operable and transportable by a single individual.
A variety of cementious materials are used in the construction industry. A segment of these materials consist of cements formed from very thin slurries. These materials are so thin in comparison to the relatively thick and stiff common cements, grouts, and mortars, that they require specialized equipment and handling techniques to implement. These thin materials are generally transported to a job site in a large truck, and transferred to the work area by pumping through hoses. Because of the need for large and extensive specialized equipment, and the great number of workers required to operate the equipment, the economic cost of implementing the thin cementious material has prevented it from being used in small-scale construction applications.
An example of the thin cementious material is a specialized gypsum cement commercially known as xe2x80x9cGypcretexe2x80x9d. These materials are currently used as self-leveling underlayment cements for leveling floors, as a thermal mass for radiant heat flooring, for acoustic insulation and as a flooring fire retardant. If these products were more portable, excellent results could be found transferring commercial-scale applications to small-scale jobs. Additionally, a portable mixing device would allow use of gypsum cements in jobs having limited access. For instance a portable mixing device could be used in upper stories of a high rise building. In urban areas, where parking and traffic make use of big equipment difficult and expensive, a portable mixing device would provide an economical and logistical solution.
The inventive portable mixing device allows quick and efficient combination of dry constituents with water to form a mix having a thin batter consistency, no lumps, and no unmixed material. Mounted on a wheeled, pivoting frame, a single individual can use the portable mixing device to mix the material and pour it in the proper location. In this way, the possible applications of this material are greatly expanded, since the material can now be used in a greater variety of applications and for smaller scale projects.
The inventive portable mixing device includes a cylindrical mixing drum which houses an agitation tool and which is mounted to a pivoting, wheeled frame. The agitation tool includes a motor and housing, a drive shaft, wiping assembly, and mixing assembly. The stationary wiping assembly, which extends downward into the mixing drum comingles so as to pass closely between and among the blades of the rotating mixing assembly such that the flexible edge portions of the wiping assembly blades are in intermittent contact with the blades of the mixing assembly. The xe2x80x9cwipingxe2x80x9d action of the wiper assembly on the mixing assembly insures complete and efficient agitation and mix of materials.
The motor resides within a motor housing, and the motor housing is fixed to the frame so as to reside above the open top end of the mixing drum and so that the drive shaft extends from the motor downward into the mixing drum.
The wiping assembly is made up of a set of elongate blades which are provided with flexible edge portions. The wiping assembly is stationary, being fixed to the motor mount and extending downward into the mid portion of the mixing drum so as to lie generally parallel with the drive shaft.
The mixing assembly is made up of a second set of elongate blades which are fixed to and rotationally driven by the drive shaft. The blades of the mixing assembly extend generally vertically upward from the lower end of the mixing drum so as to pass closely between and among the blades of the wiping assembly. During operation, the flexible edge portions of the wiping assembly blades are in intermittent contact with the rotating blades of the mixing assembly. The flexible edge portions sweep across the surface of mixing blade to remove any accumulation of unmixed material therefrom thus greatly increasing the efficiency of agitation within the mixing drum.
Because the mixing drum is vertically oriented during agitation, elements have been included which are designed to prevent dry components from settling to the bottom of the mixing drum and remaining unmixed. The first such element includes xe2x80x9cLxe2x80x9d shaped mixing assembly blades which are positioned adjacent to the mixing drum wall near the bottom of the mixing drum. These blades are mounted at an acute angle relative to the vertical so as to drive the mix upward to the mid portion of the drum during agitation. Additionally, the bottom edge of the xe2x80x9cLxe2x80x9d is radially aligned and extends radially from the drum wall toward the centerline of the mixing drum so as to co-mingle and interact with the second element.
The second element which is designed to prevent dry components from settling to the bottom of the mixing drum and remaining unmixed are a pair of horizontally extending bars which are fixed to and are spaced to lie above the bottom surface of the mixing drum. These bars agitate material which is dislocated from resting on the bottom surface by the sweeping action of the bottom edge of the xe2x80x9cLxe2x80x9d shaped mixing assembly blades.
The wheeled support frame of the inventive portable mixing device allows the mixing drum to selectively pivot between two positions. The first upright position is used during agitation of materials within the mixing drum. In this position, the longitudinal axis of the mixing drum is vertical and the top end of the mixing drum overlies its bottom end. The second tipped position is used to pour out the contents of the mixing drum. In the second position, the longitudinal axis of the mixing drum is no longer vertical and the top end of the mixing drum is positioned below the bottom end of the mixing drum.